So-called vectoring or vectored data transmission is a technique for coordinated transmission or reception of data from a plurality of transmitters to a plurality of receivers via a plurality of communication connections in order to improve the transmission, for example to reduce the influence of crosstalk. Either transmitters or receivers are co-located.
For example, in DSL (digital subscriber line) transmission systems, for example VDSL (very high bit rate DSL) transmission systems, data may be transmitted from a central office (CO) or other provider equipment to a plurality of receivers located in different locations, for example in customer premises (CPE), via a plurality of communication lines. Crosstalk resulting from signals on different lines transmitted in the same direction, also referred to as far end crosstalk (FEXT), may result in a reduced data throughput. Through vectoring, signals transmitted over the plurality of communication lines from the central office or received via the plurality of communication lines in the central office may be processed jointly in order to reduce such crosstalk, which joint processing corresponds to the above-mentioned vectoring. In this respect, the reduction of crosstalk by coordinated transmission of signals is sometimes referred to as crosstalk precompensation, whereas the reduction of crosstalk through joint processing of the received signals is sometimes referred to as crosstalk cancellation. The communication connections which are processed jointly are sometimes referred to as vectored group.
Both at the initialization of communication and during communication, it may be necessary to add an additional communication connection to the vectored group, for example when an additional user of a DSL service becomes active. In such a case, it is generally desirable to minimize the influence of this joining of a new communication connection on the data transmission occurring in the communication connections already in the vectored group.